Arrangement for the generation of unipolar air ions

ABSTRACT

The arrangement includes a gas discharge lamp, preferably a glow lamp, comprised of a glass wall defining an enclosed space and at least one electrode located in the enclosed space and spaced from at least a predetermined portion of the glass wall by a distance less than 10 millimeters. A conductor having a tip portion located exteriorly of said glass wall but proximal to said predetermined portion of said glass wall is connected to a D.C. potential. The electric field established at the tip portion of the conductor interacts with the ultraviolet radiation produced by the gas discharge lamp to produce unipolar air ions.

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States Patent Von Berckheim 1 ARRANGEMENT FOR THE GENERATION OF UNIPOLAR AIR IONS [76] Inventor: Constantin Graf Von Berckhei n,

Friedrichstrasse 9, Weinheim, Germany [22] Filed: Nov. 29, 1973 [21] Appl. No.: 420,171

[30] Foreign Application Priority Data Dec. 11, 1972 Germany 2260521 [52] US. Cl. 317/4 [51] Int. Cl. H01t 19/00 [58] Field of Search 317/4; 313/63, 230, 234, 313/201 [56] References Cited UNITED STATES PATENTS 3,047,718 7/1962 Fleming et a1. 317/4 l/l963 Minto 317/4 4/1964 Allen et a1. 317/4 [5 7 ABSTRACT The arrangement includes a gas discharge lamp, preferably a glow lamp, comprised of a glass wall defining an enclosed space and at least one electrode located in the enclosed space and spaced from at least a predetermined portion of the glass wall by a distance less than 10 millimeters. A conductor having a tip portion located exteriorly of said glass wall but proximal to said predetermined portion of said glass wall is connected to a DC. potential. The electric field established at the tip portion of the conductor interacts with the ultraviolet radiation produced by the gas discharge lamp to produce unipolarair ions.

14 Claims, 3 Drawing Figures ARRANGEMENT FOR THE GENERATION OF UNIPOLAR AIR IONS BACKGROUND OF THE INVENTION The invention relates to an arrangement for the generation of unipolar air ions, especially for the electric climate control of interier spaces, of the type in which the radiation of a gas discharge lamp and the steady electric field of a wire tip cooperate with each other.

German Pat. No. 1,679,491 discloses a gas discharge tube on whose glass body fine wire-like spikes are lightly and resiliently supported. For example the gas discharge tube can be a conventional fluorescent tube operated with a conventional tube driving voltage, particularly an A.C. voltage. A large number of these wires are mounted on a rod-shaped carrier connected to a high-voltage DC. voltage source. In the operation of the arrangement, the ultraviolet radiation produced by the gas discharge produces such an excitation in the vicinity of the wire tips as to result in the production of ions under the influence of the electrical field, without the undesired generation of ozone and nitrogen oxide.

SUMMARY OF THE INVENTION It is an object of the present invention to devise an ionization arrangement of the type in question which maintains the high level of ionization of the prior-art devices but which is of a markedly smaller size than the prior-art devices.

This object can be solved according to the invention by employing for the gas discharge lamp a glow lamp having at least one electrode the cathode of the lamp is driven by a DC. voltagespaced from the glass wall by a distance less than mm, preferably less than 7 mm, with a wire tip of the type mentioned above positioned in this region.

Glow lamps having these dimensions are very small gas discharge lamps. Correspondingly small is the number of wire tips which can be associated with such a small lamp. Also, glow lamps in general have a relatively small ultraviolet radiation output. However, if the wire tip is positioned relatively close to the electrode (e.g., the cathode in a DC. operated glow lamp) and thereby in the glow discharge region, the actually rather weak ultraviolet radiation in the region of the wire tip will be so effective that even when only one wire tip is employed ions will be produced in a quantity corresponding to that produced with a gas discharge tube provided with many wire tips.

The region in which the wire tip can be arranged can be increased in size, despite the small size of the glow lamp, if the glow lamp has a glass wall in the form of a thin pipe with surface electrodes extending parallel to the pipe-shaped glass wall. According to another approach, the glow lamp has at its front side an approximately hemispherical closed glass wall and at least two surface electrodes extending substantially parallel to such front wall. In such case, the tolerances for the position of the wire tip can be relatively large, which greatly simplifies assembly, and which furthermore makes the structure suitable for rugged uses, such as in an automotive vehicle, in which the position of the wire tip may change during operation of the arrangement.

Advantageously, use is made of a glow lamp having an average power density in its gas space of at least 0.1 W/cm, preferably more than 0.5 W/cm. This leads to a very strong glow discharge with a corresponding increase of the ultraviolet radiation. Such power densities can be achieved relatively easily with very small glow lamps. In particular, the gas spaces of the lamps can advantageously be smaller than 3 cm preferably smaller than 1 cm According to a further advantageous concept of the invention, care should be taken to assure that the surface temperature of the glow lamp, by reason of the heating action of the lamp current, be kept at least 10C above the ambient temperature. The effect of this heating is to prevent the glass surface of the glow lamp from becoming misted, under all operating conditions, and in particular when the lamp is located in warm and humid air. This is to prevent the possibility that a layer of moisture could result in the development of a shortcircuit between the wire tip connected to high voltage and the terminal of the glow lamp connected to low voltage. Also, the heating-up in the region of the wire tip leads to a greater energization, which improves the ionization production.

For glow lamps with high power densities in the gas spaces thereof, it may be sufficient to employ for the heating energy only the energy developed in the glow lamp. In other cases, it is advantageous to heat the glow lamp by means of its series resistor. This series resistor is in general present anyway. With compact constructions, for example if the series resistor is contained within the base portion of the glow lamp, the heat energy developed by the series resistor can be transferred to the glass wall of the glow lamp.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic depiction of the embodiment of the invention;

FIG. 2 is a schematic sectional view through a second embodiment of the invention; and

FIG. 3 is a sectional view, taken on line CC of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 1 designates in general a glow lamp of small dimensions. The lamp 1 projects through an opening 2 in a cover plate 3 and has a threaded base portion screwed into a threaded lamp holder 5. A series resistor 6, shown in broken lines, is contained in the base portion of the lamp 1. A first electrode 7 is connected, via series resistor 6, to connection terminal 8. The second electrode 9 is electrically connected to the peripheral portion of the metallic base portion of the lamp 1. A glass wall 12 ofa material through which ultraviolet radiation can readily pass surrounds the gas space 12 of the lamp and has a hemispherical front wall 13. This glow lamp is driven in conventional manner by an AC. voltage source 14, which is grounded at 15.

A wire 16 having a fine end tip 17 is held in a support 18 in such a manner that it rests upon the front wall 13. The support 18 is held on the cover plate 3 by the intermediary of an insulator body 19. The wire 16 is connected, via a protective resistor 20, to the nongrounded terminal of a highvoltage DC. voltage source 21.

The electrode 7 is a spherical section, and is all across its spherical surface portion substantially equidistantly spaced from the hemispherical front wall 13. This distance, designated a in FIG. 1, should according to the invention be less than 10 mm, and preferably less than 7 mm. As a result of this, if only electrode 7 is considered (i.e., if it serves as the cathode for a DC.- driven lamp), there is createda region of the glass wall 11 above the line AA characterized by the aforementioned condition. The electrode 9 is a ring whose peripheral surface is either inclined or concave. Accordingly, if a glow discharge occurs at both electrodes, which is the case with A.C.-driven 'glow lamps, the aforementioned condition will prevail in the region of the glass wall 11 above the line BB. The wire 16 can easily be arranged in such a manner that the wire tip 17 is located near this region of the glass wall.

An arrangement like that shown in FIG. 1 was constructed and tested, with a stream of air being conducted across the upper surface of the cover plate 3,

the test data being as follows:

diameter of wall of glow lamp 25 mm distance a 6.5 mm voltage of A.C. voltage source 14 220 V voltage of DC. voltage source 2] 1000 V Average power density in gas space of lamp 0.087 W/cm surface temperature of lamp with ambient temperature of 25C 40-50C number of ions emitter hourly l to In the embodiment shown in FIGS. 2 and 3, the glow lamp 22 has a pipe-shaped glass wall 23 closed off at both ends by contact plates 24 and 25. The contact plate 24 carries an electrode 26; the contact plate carries an electrode 27. Each of these electrodes 26, 27 has a cross-sectional profile corresponding to the arc of a circle, as seen particularly clearly in FIG. 3. Accordingly, the surfaces of the electrodes 26, 27 are spaced from the near surface of glass wall 23 by a constant radial distance. A springy contact 28 presses the glow lamp 22 against a stationary contact 29 provided with a quadratic recess 30 which accommodates the contact plate 24. Again, there is provided a carrier member 31 (FIG. 3) for a wire 32 having a fine tip 33 positioned alongside the glow lamp 22.

The outer diameter of the pipe-shaped glass wall 23 is 6 mm. The small radial distance between the electrodes 26, 27 and the glass wall 23 is less than 1 mm, and the largest distance less than 5 mm. As a result, the wire tip 33 can be positioned at any arbitrarily selected position over a very substantial portion of the surface of the glass wall 233. In the case of an A.C.-driven lamp the wire tip 33 can be positioned almost anywhere along the whole length of the lamp, and such tolerance range will not result in an impermissible reduction in the ion output.

The structure shown in FIGS. 2 and 3 was built and tested, the test data being as follows:

length of the glow lamp 28 mm outer diameter of the glass wall 6 mm series resistor 18 K A.C. voltage supply 220 V -Continued operating current 5.5 mA DC. voltage supply 1000 V average power density in gas space ca. 1.0 W/cm surface temperature of glass wall at an ambient temperature of 25C 50-60C number of ions emitter hourly 10 to 10 electrostatic filter, and in many other applications.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions dif fering from the types described above.

While the invention has been illustrated and described as embodied in an arrangement for producing unipolar ions, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended:

1. An arrangement for the production of unipolar air ions, particularly for the electrical climate control of habitable enclosed spaces, comprising, in combination, a glow lamp comprised of a glass wall defining an enclosed space containing two spaced electrodes, at least one of said electrodes being spaced from a predetermined portion of said glass wall by a distance less than 10 millimeters; means connected across said electrodes and operative for establishing thereacross a potential difference producing a glow discharge in the immediate vicinity of at least said one of said electrodes; and means operative for establishing a DC. electric field which interacts with the ultraviolet radiation emitted in said glow discharge to produce said unipolar air ions, and including an electrical conductor having a tip portion located outside the enclosed space defined by said glass wall but in the immediate vicinity of said predetermined portion of said glass wall, so as to be located close to said glow discharge, and means for maintaining said tip of said electrical conductor at a high D.C. potential.

2. The arrangement defined in claim 1, wherein said tip portion is located in contact with said predetermined portion of said glass wall.

3. The arrangement defined in claim 1, wherein said one of said electrodes is spaced from said predetermined portion of said glass wall by a distance less than 7 millimeters.

4. The arrangement defined in claim 1, wherein said glass wall has the form of a glass tube, and wherein said one of said electrodes is an elongated electrode extending parallel to said glass tube.

5. The arrangement defined in claim 1 wherein said glass wall is comprised of a hemispherical portion, and wherein said one of said electrodes has a portion so configurated and oriented relative to said portion of said wall as to be spaced from the latter by a substantially constant radial distance.

6. The arrangement defined in claim 1, wherein said glow lamp has a power density of at least 0.1 W/cm in the gas space thereof.

7. The arrangement defined in claim 1, wherein said glow lamp has a power density of at least 0.5 W/cm in the gas space thereof.

8. The arrangement defined in claim 1, wherein said glass wall defines an interior gas space having a volume less than 3 cm 9. The arrangement defined in claim 1, wherein said glass wall defines an interior gas space having a volume less than 1 cm 10. The arrangement defined in claim 1, wherein said means for establishing a DC. electric field comprises only one such conductor having a single tip portion located proximal to said predetermined portion of said glass wall.

11. The arrangement defined in claim 1, wherein the flow of current through said glow lamp produces suffi cient heat to maintain the surface of said glass wall at a temperature at least 10C higher than ambient temperature.

12. The arrangement defined in claim 1, wherein the flow of current through said glow lamp produces sufficient heat to maintain the surface of said glass wall at a temperature between 15 and 30C higher than ambient temperature.

13. The arrangement defined in claim 11, wherein said glow lamp includes a series resistor which carries the glow lamp current and is so positioned with respect to said glass wall as to maintain the surface of said glass wall at a temperature at least 10C higher than ambient temperature.

14. The arrangement defined in claim 12, wherein said glow lamp includes a series resistor which carries the glow lamp current and is so positioned with respect to said glass wall as to maintain the surface of said glass wall at a temperature between 15 and 30C higher than ambient temperature. 

1. An arrangement for the production of unipolar air ions, particularly for the electrical climate control of habitable enclosed spaces, comprising, in combination, a glow lamp comprised of a glass wall defining an enclosed space containing two spaced electrodes, at least one of said electrodes being spaced from a predetermined portion of said glass wall by a distance less than 10 millimeters; means connected across said electrodes and operative for establishing thereacross a potential difference producing a glow discharge in the immediate vicinity of at least said one of said electrodes; and means operative for establishing a D.C. electric field which interacts with the ultraviolet radiation emitted in said glow discharge to produce said unipolar air ions, and including an electrical conductor having a tip portion located outside the enclosed space defined by said glass wall but in the immediate vicinity of said predetermined portion of said glass wall, so as to be located close to said glow discharge, and means for maintaining said tip of said electrical conductor at a high D.C. potential.
 2. The arrangement defined in claim 1, wherein said tip portion is located in contact with said predetermined portion of said glass wall.
 3. The arrangement defined in claim 1, wherein said one of said electrodes is spaced from said predetermined portion of said glass wall by a distance less than 7 millimeters.
 4. The arrangement defined in claim 1, wherein said glass wall has the form of a glass tube, and wherein said one of said electrodes is an elongated electrode extending parallel to said glass tube.
 5. The arrangement defined in claim 1, wherein said glass wall is comprised of a hemispherical portion, and wherein said one of said electrodes has a portion so configurated and oriented relative to said portion of said wall as to be spaced from the latter by a substantially constant radial distance.
 6. The arrangement defined in claim 1, wherein said glow lamp has a power density of at least 0.1 W/cm3 in the gas space thereof.
 7. The arrangement defined in claim 1, wherein said glow lamp has a power density of at least 0.5 W/cm3 in the gas space thereof.
 8. The arrangement defined in claim 1, wherein said glass wall defines an interior gas space having a volume less than 3 cm3.
 9. The arrangement defined in claim 1, wherein said glass wall defines an interior gas space having a volume less than 1 cm3.
 10. The arrangement defined in claim 1, wherein said means for establishing a D.C. electric field comprises only one such conductor having a single tip portion located proximal to said predetermined portion of said glass wall.
 11. The arrangement defined in claim 1, wherein the flow of current through said glow lamp produces sufficient heat to maintain the surface of said glass wall at a temperature at least 10*C higher than ambient temperature.
 12. The arrangement defined in claim 1, wherein the flow of current through said glow lamp produces sufficient heat to maintaIn the surface of said glass wall at a temperature between 15* and 30*C higher than ambient temperature.
 13. The arrangement defined in claim 11, wherein said glow lamp includes a series resistor which carries the glow lamp current and is so positioned with respect to said glass wall as to maintain the surface of said glass wall at a temperature at least 10*C higher than ambient temperature.
 14. The arrangement defined in claim 12, wherein said glow lamp includes a series resistor which carries the glow lamp current and is so positioned with respect to said glass wall as to maintain the surface of said glass wall at a temperature between 15* and 30*C higher than ambient temperature. 